Menaquinone biosynthesis in Bacillus subtilis: isolation of men mutants and evidence for clustering of men genes

Abstract

Menaquinone (vitamin K2)-deficient mutants of Bacillus subtilis were selected by ultaneous resistance to two aminoglycoside antibiotics. These men mutants fell into two groups: group I, in which the nutritional requirement was satisfied either by o-succinylbenzoic acid or by 1,4-dihydroxy-2-naphthoic acid; and group II, comprising those capable of growing only when supplemented with 1,4-dihydroxy-2-naphthoic acid. The latter group could be further subdivided into two classes on the basis of syntrophy experiments, fine-structure genetic mapping, and in vitro complementation by cell-free extracts (Meganathan et al., J. Bacteriol., 145:328-332, 1981). These subclasses of group II defined the menB and menE genes, whereas group I appeared to comprise mutations in the menC and menD genes. All of the men mutations tested, whether occurring in menB, menE, or menC,D, could be placed by genetic mapping with bacteriophage PBS1 between bioB and aid on the B. subtilis genome.

Map locations and functions of Salmonella typhimurium men genes

“…typhimurium men mutants, when tested by streaking side by side on glycerol fumarate or glycerol TMAO plates (7), did not cross-feed each other. Similarly negative results were obtained in the studies of men mutants in E. coli (4, 5), although such cross-feeding studies were successful in Bacillus subtilis (12). However, we found that cross-feeding with respect to providing intermediates for H2S production was easily detected.…”

Menaquinone synthesis is critical for maintaining mycobacterial viability during exponential growth and recovery from non‐replicating persistence

“…It has previously been shown that Gram-positive bacilli are capable of utilizing exogenous DHNA to satisfy nutritional requirements in organisms with mutations in genes upstream of MenA (Meganathan et al, 1981;Taber et al, 1981); thus, the observation that addition of DHNA to the culture medium does not rescue bacterial growth in the presence of Ro 48-8071 indicated that the inhibition likely occurs at a step in menaquinone biosynthesis downstream of the action of MenB, a hypothesis supported by the observation that Ro 48-8071 specifically inhibits MenA activity in vitro.…”

Biosynthesis of vitamin K (menaquinone) in bacteria.

“…men Mutants of Bacillus subtlis Mutants of B. subtilis, an organism that does not contain ubiquinone, were obtained by nitrosoguanidine treatment and were selected by simultaneous resistance to two aminoglycoside antibiotics by Taber and his colleagues (209). The use of aminoglycoside antibiotic resistance for the selection of men mutants derives from the role of quinones in transport of these antibiotics into the bacterial cell (36,210).…”